In order to cause a robot to correctly operate functions of feedforward, collision detection, etc., it is necessary to obtain load parameters, such as the mass, the position of the center of gravity, and the inertia matrix, of a load that is attached to the robot or a load that is grasped by a hand attached to the robot. In the related art, if the load parameters are unknown, estimation of the load parameters is performed.
For example, Japanese Unexamined Patent Application, Publication No. Hei 03-55189 discloses a technique in which a load is attached via a force sensor, and a load parameter is estimated from a plurality of orientations and an output of the force sensor.
Furthermore, for example, Japanese Unexamined Patent Application, Publication No. Hei 10-138187 discloses a technique in which an operation pattern program is created according to a taught reference position, drive torque is calculated from drive currents of respective axes when the robot is operated according to the created operation pattern program, thereby estimating unknown load parameters on the assumption that this drive torque matches a load torque that includes an unknown mass and center-of-gravity position of the load.